Bringing My VNA into the 21st Century - HP 8714C LCD Upgrade

[@infi84]

poor little CRT, I sure hope it will go to someone who'll treasure it and not into the trash.

[@gorak9000]

When measuring mounting studs, instead of doing inside and outside measurements, measure one bolt and zero the calipers. Then measure outside to outside - that's the center to center distance! You've subtracted 1/2 a bolt width on each side by zeroing on one bolt!

[@w3axl]

@@gorak9000 Filing that one away for future reference. Smart!

[@gorak9000]

@@w3axl works good on mounting holes too - measure one hole inside, then zero, then measure outside edge to outside edge across both holes using the inside side of the calipers - no need to 'estimate' where the center of the hole is

[@BartKus]

That was such a nice looking CRT 😕

[@cromulence]

In this application the LCD is the better option by far

[@ShedewrS]

@@cromulence Why? We used it for 20 years and everything was ok until Aliexpress came along.

[@cromulence]

@@ShedewrS OP literally described the main selling point. Multiple colours. CRTs are fetishised as these amazing things. This device is a functional utility. It doesn't need scan lines, it doesn't need perfect scaling. This LCD adds functionality, lowers weight, and is easier to replace in the future.

[@ShedewrS]

@@cromulence It's not like the VNA is a pocket knife-20 kg is perfectly manageable for a permanent lab setup. After 20 years of flawlessly running CRTs, upgrading to an LCD is clearly the groundbreaking innovation we all needed. I mean, who wouldn’t want to deal with replacing capacitors and some precise resistors to restore the factory measurement accuracy? It's better just add a color. Why not use a small external LCD monitor with a VGA input for those occasional needs for color lines instead of modifying a perfectly functioning CRT? Plus, what will you do with the removed CRT? Will it end up in the trash, stored until it eventually breaks, or left to gather dust without proper recycling? I can understand the reason 'I don't have money, so I'll show you how to cheaply create something similar to modern technology for a student and a novice technician using a grandpa's oscilloscope/VNA' - vandalism out of necessity. But replacing a working display just for fun is not cool.

[@allesklarklaus147]

@@ShedewrS It is a monochrome green CRT. The new display displays better (in multiple ways) at lower weight and improves overall useability of the instrument so why make a complaint about it? Keep your instrument as is if you like the CRT better. And your proposal of using an external Monitor is not keeping this CRT any healthier or produces any less waste unless you explicitly use a monitor that would have gone in the trash otherwise. And it can take up quite a bit of bench space.

[@channelsixtysix066]

Yes, you'll do it once, learn from the experience and never, ever do it again. 08:03 Your presentation style reminds me of another great YT engineering channel, _This Old Tony_ . Cheers.

[@SlayaOneTwelve]

Awesome mod! As long as this equipment is used for the purposes of performing work, and not fulfilling some need for nostalgia, the new LCD screen will excellent upgrade. The additional colors convey information, and the screen itself seems easier to read.

[@dimBulb5]

Nice job! I love a good old CRT, but this upgrade will be much more useful.

[@lmamakos]

Nice! Thanks for walking through the modeling process for the bracket. It's always useful to see how people approach those problems.

[@theodricaethelfrith]

The mod is very well executed, but I feel losing the CRT is a net negative. To each their own.

[@Stoney3K]

If you're lucky the ribbon cable has plain VGA on it as well as +12v, judging by the pin count that's very possible. That would make the entire module a complete drop-in replacement without any weird wiring going through the outside. The fact that they marketed the colour output as an upgraded model makes me wonder why the internal monitor wasn't replaced by a color VGA one since those were pretty common in the 90s.

[@nixxonnor]

[@TMS5100]

Instead of vinyl tape, I think you could 3d print inserts which would attach to the front four sides of the mounting bracket, and fill in the curved bezel gaps. theres enough space in the middle of the front four sides to figure out how to attach the inserts, so the fact that the corners are flush is not a problem. if you print the inserts the correct orientation, you would get a nearly infinitely smooth curve instead of the stairstep you saw in the eevblog pic.

[@michvod]

Nice proof of concept, but it looks kinda cheap, especially as the front bezel isn't covering the sides of the LCD panel. That CRT wasn't worn out, at least from what I could see.

[@pem1200]

you could use a ruler as a scale and take a picture and scale it to the ruler

[@MrBearr.]

I came into the video wondering why you replace a perfectly working tube for a LCD, until you said that the display has color out of the VGA port. You should check the power consumption difference between the LCD and the CRT.

[@ruhnet]

Looking forward to part 2! :) 73s

[@JorgeALXNDR]

what a video to watch on the bathroom throne

[@Stoomtronic]

How about removing some plastic from the inside of the front cover (mostly in the Z-direction I think) to create room for a nice 3D printed bezel.

[@johnkelly7264]

Super interesting... subbed here.

[@mbirth]

It's a shame you have to sacrifice the VGA port for this. With Tektronix oscilloscopes, there usually is a (slightly more expensive) way to use the signal from the video board directly and keep the VGA port.

[@timballam3675]

Get a bit of Melamine faced chipboard fit in place of screen, use two part filler to fill in gaps around screen, remove board and clean up filler. (paint if required) Profit 🤟

[@nixxonnor]

Be aware that the screw set is NOT suitable for kids under 6 years due, ref time stamp 17:30

[@tomascernak6112]

this is just crime.

[@SmoggyLambGG]

⚡ High voltages inside.

[@OldePhart]

I did indeed notice you spared no expense on the studio 😉 Happy New year!

[@Subgunman]

Most any CRT equipped test gear that has a VGA OUTPUT to it is capable of this conversion. Well worth the time in what you will gain in weight reduction.

[@brianfox7067]

This is heresy

[@n3lee]

i had to hack mine together with parts from my 8711 but would love to know more on where you got the parts!

[@ShedewrS]

I don't like it, now it looks like a 250 bucks oscilloscope from Aliexpress

[@allesklarklaus147]

not in that formfactor lol

[@OLIBAHN475]

ich gerne bildröhren.

LCD downgrade

[@3a.m.284]

Cool you made it worse. Congrats